As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: AFT FUEL PUMP 1 LOW PRESSURE ILLUMINATED UPON TURNING ON AT GATE THEN CAME BACK ON AGAIN AT CRUISE UPON BALANCING FUEL. REMOVE AND REPLACED LEFT HAND WING AFT FUEL PUMP PRESSURE SWITCH. PER MM 28-42-11. OPS CHECK GOOD.